plugins - examples and (more) docs

plugins - examples and (more) docs

[Martin Gasthuber]

Hi,

   for our large storage system holding half a petabyte of experimental 
physics data, we are looking for a new nameservice implementation. 
Roughly this means - just store filenames in a hierarchical fashion (as 
usual) but only store metadata (from the other storage system components 
i.g. disk-cache and tape store) and no real data (this is in the cache - 
one or more times, and the 'real' copy is on tape). Right now we have a 
DB (simple key/value) system with a faked NFS server code on top.
While looking at other ways and making proof of concept implementation i 
'traped' into reiser4 with the important plugin feature. For our system 
we need 'unique + persistent' IDs for files with the ability to map in 
both directions (name -> id, id -> name), extended attributes and 
virtual files. From what i understand, reading the reiser4 docs i've 
found, all this should be feasible by creating new plugins for files and 
IDs. Because i like 'real' stuff - im' looking for plugin example code 
and more docs related to plugin creation and integration. Any idea where 
i can find that ???

Regards,
   Martin

Re: plugins - examples and (more) docs

[Hans Reiser]

Martin Gasthuber wrote:

> Hi,
>
>   for our large storage system holding half a petabyte of experimental 
> physics data, we are looking for a new nameservice implementation. 
> Roughly this means - just store filenames in a hierarchical fashion 
> (as usual) but only store metadata (from the other storage system 
> components i.g. disk-cache and tape store) and no real data (this is 
> in the cache - one or more times, and the 'real' copy is on tape). 
> Right now we have a DB (simple key/value) system with a faked NFS 
> server code on top.
> While looking at other ways and making proof of concept implementation 
> i 'traped' into reiser4 with the important plugin feature. For our 
> system we need 'unique + persistent' IDs for files with the ability to 
> map in both directions (name -> id, id -> name), extended attributes 
> and virtual files. From what i understand, reading the reiser4 docs 
> i've found, all this should be feasible by creating new plugins for 
> files and IDs. Because i like 'real' stuff - im' looking for plugin 
> example code and more docs related to plugin creation and integration. 
> Any idea where i can find that ???
>
> Regards,
>   Martin
>
>
You are right that this is doable, for examples see our source code 
which is much better commented than the rest of the kernel (disclaimer: 
akpm code is better commented than ours).